Antibiotics -- the wonder drugs of the 20th century -- are gradually losing their clout. Bacteria naturally develop resistance to antimicrobial drugs. In recent years, however, overuse of antibiotics has caused a growing number of staphylococcus bacteria to evolve into disease-causing "superbugs" resistant to drugs like methicillin. Hospital patients with MRSA -- a potent antibiotic-resistant staph infection -- are four times as likely to die as other patients. Moreover, while most superbugs once thrived only in hospitals, new strains outside health facilities are killing healthy people. Adding to the concerns of public-health officials, drug companies are developing few new antimicrobials. Some activists urge strong curbs on all antimicrobial use, including to promote fast growth in farm animals. Others oppose legal requirements for animal or human antibiotics, arguing that voluntary efforts are better able to keep pace with the fast-evolving world of microbes.

Marcia Clemmitt is a veteran social-policy reporter who joined CQ Researcher after serving as editor in chief of Medicine and Health, a Washington-based industry newsletter, and staff writer for The Scientist. She has also been a high school math and physics teacher. She holds a bachelor's degree in arts and sciences from St. Johns College, Annapolis, and a masters degree in English from Georgetown University.